Autophagy - How Our Body Performs a Self-Renewing Process

There's definitely much more to it than meets the eye, of course.

Our bodies consist of approximately 38 trillion cells. These cells are present in just about every part of our body as parts of various different systems and carry out various different functions to support the health of the human body as a whole.

The human body, therefore, can be likened to an organisational structure. In the grand scheme of things, an employee who works in a company is part of that company’s system.

There will exist multiple different departments within that organisation, each department having its own system to operate — some departments deal with internal organisational functions, such as Human Resources (HR) or Information Technology (IT).

Without those departments, an employee may not be able to work efficiently with current technological tools, or they may not get paid their wages promptly.

There are other departments that deal with the external side of things, such as the sales department, which focuses on providing solutions for clients. A person who is working in HR would not necessarily be suited to work in sales, for instance.

All these individual departments have mid level managers and higher level management tiers, who are present to regulate the workflow and the tasks that are required for each department to function and to improve.

Communication is key for each department to be on the same page — hence emails, messenger apps and phone calls are necessary to get messages sent across effectively. A nastily worded email can create its own issues inasmuch as a vague email can cause confusion.

The cells in a system are responsible for performing different functions. In our digestive system, for instance, we have the parietal cells in the stomach that are responsible for producing the gastric acids needed for food digestion, and we have various cells in the liver that detoxify various substances, which can then be eliminated via a liquid channel (urine) or solid channel (faeces).

As a corporate organisation conducts routine renewals to maintain its productive efficiency (via firing, hiring and the dreaded annual performance reviews), many of the cells in our systems also do undergo that form of routine renewal.

Cellular function and renewal

Most cells are able to reproduce asexually via binary fission. The parent cell is able to split up into 2 daughter cells during reproduction, and it can then carry on the work of the parent cell.

Inefficiently operating cells are “fired” from the efficiency standpoint, because business is business.

When they are earmarked for firing, they get tagged by the p62 protein and are marked for elimination, much like how a defective product at a supermarket is tagged for disposal, or marked down at a discounted price (for the customer to dispose of it).

However, a living cell will not go out without a fight — it has to be put down via apoptosis first, where it is “programmed” to commit suicide. As it is written in this article:

Apoptosis is described as an active, programmed process of autonomous cellular dismantling that avoids eliciting inflammation.

Therefore, a cell that is earmarked for elimination will be first programmed to commit suicide via apoptosis.

Once a cell has undergone apoptosis, it should be disposed of via phagocytosis and autophagy, where it can be digested down completely. Phagocytosis deals with extracellular materials (outside the cell), while autophagy deals with intracellular materials (within the cell).

In fact, dead foam cells in atherosclerotic plaques can be removed via efferocytosis, which is similar to autophagy:

Much like how a company laptop can be wiped clean when an employee leaves a company, such that the next new incoming person can continue using the same laptop.

When the speed of autophagy/phagocytosis is reduced, the (already dead) apoptotic cells tend to release pro-inflammatory biochemical products, much like how a dead body that is left on the streets will decompose and give off noxious odours if it is left uncleared on the streets.

The thing is that the dead cells have to be removed ASAP.

Much like how we want dead bodies or rubbish to be cleared off the streets by the waste disposal units ASAP. The stench given off by rotting food or dead bodies can be terribly unpleasant, and it can attract other unpleasant scavenger species along the way to worsen the conditions of the streets.

In the human body, the dead apoptotic cells will continue contributing to the pro-inflammatory environment, which can spell trouble for other biochemical processes in the body.

Because our immune system also relies on this procedure to tag and eliminate virus-infected cells, for instance. The p62 protein has to scour the body for any virus-infected cell to tag it and programme it to commit suicide first.

(Otherwise, this virus-infected cell is just going to do the bidding of the virus. Its DNA/RNA replication mechanism would have been hijacked by the virus to only produce new copies of virus DNA/RNA strands, which can exit the hijacked cell and proceed to infect other healthy cells.)

The infection rate would increase exponentially. All it needs is one hijacked cell to kick off the entire process.

Hence the tagging speed has to be maintained at a sufficient level to ensure that all these infected cells are programmed to commit suicide via apoptosis.

These apoptotic infected cells can then be dismantled via autophagy/phagocytosis before they can cause any more damage to other healthy cells.

As we can see, our immune system has to be functioning optimally to ensure that all threats to the body are dealt with swiftly and efficiently.

If the foundational defensive mechanisms of apoptosis and autophagy/phagocytosis can deal with a viral infection, we wouldn’t necessarily even feel any symptoms of a flu infection.

But if these mechanisms cannot cope, the matter would have to be escalated up to the higher order cells in the immune system, with potentially more severe consequences such as a looming cytokine storm - much like in a corporate organisation, even.

If a lower level employee can deal with a “threat” without having to escalate matters to their immediate supervisors, the consequences would be less severe.

However, if the issue is so serious that it has to go all the way up to the CEO, we can expect more drastic measures to be taken.

Even as COVID-19 took the world by storm in the past few years, it was noted that the obese and diabetics were people who were at higher risk of developing cytokine storms. Even those with heart disease were also also at higher risk.

Probably because their autophagy mechanisms were already dysregulated to begin with, no?

And it’s also the heart disease patients whose dysregulated autophagy mechanisms are unable to eliminate the necrotic cells in their own atherosclerotic plaques, which makes them even more susceptible to a heart attack, no?

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